Changes to the Highland Mainline timetable and developments?

Status
Not open for further replies.

Railperf

Established Member
Joined
30 Oct 2017
Messages
2,470
Mod Note: Posts #1 - #14 originally in this thread.

Weren't there plans to introduce an hourly HML service each way eventually?
 
Sponsor Post - registered members do not see these adverts; click here to register, or click here to log in
R

RailUK Forums

hexagon789

Veteran Member
Joined
2 Sep 2016
Messages
12,030
Location
Glasgow
Weren't there plans to introduce an hourly HML service each way eventually?
Yes, hourly Perth-Inverness. Essentially two-hourly each from Glasgow and Edinburgh (slightly more services from Edinburgh iirc). A mixture of semi-fast and stopping services as well.

From what I remember of the document someone posted a while back on the timetable, it reminded me a lot of the original Turbostar HML timetable with the mix of semi-fast and stopping services.
 

Railperf

Established Member
Joined
30 Oct 2017
Messages
2,470
Can any Scotrail drivers on here explain the operational limitations/ difficulties experienced on the highland main line on a daily basis.
I noted last year that at Cartridge, where 2 HST's were passing one another in the loop. It seems that one train has to be in the loop and stopped before the other one can approach. I suspect that leads to one or the other trains stopped somewhere waiting for that to happen. I'm not sure of that applies in both directions or not.
And I'm guessing the same applies to many of the other station /passing loops. Has the infrastructure upgrades/new signalling etc made a difference?

Clearly in the perfect world the HML would be double track throughout, but having mainly single track and a mixture of colour light / semaphore signalling creates havoc as soon as a train is running late. There seems to be very little ability to recover from delays.

The HST's seem to have better acceleration but worse braking than the 170's and also suffer from having to run at lower non SP speed limits.
There appear to be lots of reasonably straight /lightly curved sections of track that could allow faster speed limits, but the current line speed profile seems to have been set on the acceleration capabilities (particularly uphill) of the wheezy 170's and longer 2+8/ 2+9 HST's. There was clearly no point posting an 85mph/90mph limit on the uphill section from Dalwhinnie towards Drumochter, because neither of the legacy traction would achieve it up such steep grades. Whereas the sprightly 2+4 HST's can achieve it much more easily!
 

matchmaker

Established Member
Joined
8 Mar 2009
Messages
1,219
Location
Central Scotland
Can any Scotrail drivers on here explain the operational limitations/ difficulties experienced on the highland main line on a daily basis.
I noted last year that at Cartridge, where 2 HST's were passing one another in the loop. It seems that one train has to be in the loop and stopped before the other one can approach. I suspect that leads to one or the other trains stopped somewhere waiting for that to happen. I'm not sure of that applies in both directions or not.
And I'm guessing the same applies to many of the other station /passing loops. Has the infrastructure upgrades/new signalling etc made a difference?

Clearly in the perfect world the HML would be double track throughout, but having mainly single track and a mixture of colour light / semaphore signalling creates havoc as soon as a train is running late. There seems to be very little ability to recover from delays.

The HST's seem to have better acceleration but worse braking than the 170's and also suffer from having to run at lower non SP speed limits.
There appear to be lots of reasonably straight /lightly curved sections of track that could allow faster speed limits, but the current line speed profile seems to have been set on the acceleration capabilities (particularly uphill) of the wheezy 170's and longer 2+8/ 2+9 HST's. There was clearly no point posting an 85mph/90mph limit on the uphill section from Dalwhinnie towards Drumochter, because neither of the legacy traction would achieve it up such steep grades. Whereas the sprightly 2+4 HST's can achieve it much more easily!
You can't normally allow trains from opposite directions to enter passing loops on a single line at the same time. They can only be brought up to the home signal. Once one has entered the loop, the second can be brought in as well. The reason for this is down to the safety overlaps required by the signalling system.

I believe that when Pitlochry was resignalled, the starter signals were moved rearwards to allow two trains to approach at the same time.
 

najaB

Veteran Member
Joined
28 Aug 2011
Messages
25,151
Location
Scotland
Clearly in the perfect world the HML would be double track throughout, but having mainly single track and a mixture of colour light / semaphore signalling creates havoc as soon as a train is running late. There seems to be very little ability to recover from delays.
Shorter blocks would make it a lot easier to "flight" trains, allowing capacity increases and/or easier recovery using the passing loops that already exist. But it wouldn't be a cheap undertaking.
 

47271

Established Member
Joined
28 Apr 2015
Messages
2,967
Can any Scotrail drivers on here explain the operational limitations/ difficulties experienced on the highland main line on a daily basis.
I noted last year that at Cartridge, where 2 HST's were passing one another in the loop. It seems that one train has to be in the loop and stopped before the other one can approach. I suspect that leads to one or the other trains stopped somewhere waiting for that to happen. I'm not sure of that applies in both directions or not.
And I'm guessing the same applies to many of the other station /passing loops. Has the infrastructure upgrades/new signalling etc made a difference?

Clearly in the perfect world the HML would be double track throughout, but having mainly single track and a mixture of colour light / semaphore signalling creates havoc as soon as a train is running late. There seems to be very little ability to recover from delays.

The HST's seem to have better acceleration but worse braking than the 170's and also suffer from having to run at lower non SP speed limits.
There appear to be lots of reasonably straight /lightly curved sections of track that could allow faster speed limits, but the current line speed profile seems to have been set on the acceleration capabilities (particularly uphill) of the wheezy 170's and longer 2+8/ 2+9 HST's. There was clearly no point posting an 85mph/90mph limit on the uphill section from Dalwhinnie towards Drumochter, because neither of the legacy traction would achieve it up such steep grades. Whereas the sprightly 2+4 HST's can achieve it much more easily!
I'm not a Scotrail driver but I'm a Scotrail passenger living on the Highland Main Line and your post here describes very well how frustrating the route is. Pre Covid I spent a lot of my time stuck on trains in places like Stanley or Dunkeld just waiting for something travelling in the opposite direction to show up late.

Approach control on the loops does lose time but the real problem is a basic lack of capacity. Double tracking would be the dream, but even I as a regular user can see that the cost would be vast in relation to the likely increases in traffic.

What we need for resilience is more loops, at least three of them, as built the HML had many more, and no significant increase in service frequency. What we're going to get with the full HST timetable is an expansion in the number of trains but only the minimal capacity increases already brought by resignalling at Pitlochry and Aviemore. So in that sense the HSTs are likely to make timekeeping worse rather than better because more of them are attempting to fit into an already limited space.

I agree that line speed improvements, such as up Drumochter, would be an advance of sorts and would help with recovery from time to time. But if this is delivered against a background of no improvement in loop capacity, all that would be achieved on most days would be a 100mph run up the hill followed by a ten minute wait in Dalwhinnie station for a late running southbound service. However fast and powerful it is, a late train stuck in a loop is a late train stuck in a loop.
 

Railperf

Established Member
Joined
30 Oct 2017
Messages
2,470
Shorter blocks would make it a lot easier to "flight" trains, allowing capacity increases and/or easier recovery using the passing loops that already exist. But it wouldn't be a cheap undertaking.
Looking at it from an operational view - to run an hourly service - and assuming you could average 60mph, then your trains are going to cross each other every 30 mins or so. If the trains can be booked to leave and arrive at Inverness or Perth at around the same time - then the trains can pass each other at the main station stops half an hour apart.
The half hour sections seem to be Inverness to to Aviemore, Aviemore to Dalwhinnie, Dalwhinnie to Pitlochry , and then Pitlochry to Perth.

Your Northbound service and Southbound services ideally need to pass each other at Aviemore and Pitlochry at station stops. Timed correctly - your southbound service joins the double track at Dalwhinnie a few minuites before the northbound is set to hit the single track. Similarly, the southbound service can hit the double track at Stanley around 5 to 8 mins before the Northbound service.

If double tracking cannot be achieved throughout - would it be better to extend some of the loops into shortish double track lengths be a better idea?
 

InOban

Established Member
Joined
12 Mar 2017
Messages
3,359
Looking at it from an operational view - to run an hourly service - and assuming you could average 60mph, then your trains are going to cross each other every 30 mins or so. If the trains can be booked to leave and arrive at Inverness or Perth at around the same time - then the trains can pass each other at the main station stops half an hour apart.
The half hour sections seem to be Inverness to to Aviemore, Aviemore to Dalwhinnie, Dalwhinnie to Pitlochry , and then Pitlochry to Perth.

Your Northbound service and Southbound services ideally need to pass each other at Aviemore and Pitlochry at station stops. Timed correctly - your southbound service joins the double track at Dalwhinnie a few minuites before the northbound is set to hit the single track. Similarly, the southbound service can hit the double track at Stanley around 5 to 8 mins before the Northbound service.

If double tracking cannot be achieved throughout - would it be better to extend some of the loops into shortish double track lengths be a better idea?
Remember also that due to the availability of paths out of Waverley and, in particular, Queen Street, these trains can only depart from, or arrive into, Central Scotland at particular times each hour. It may not be possible to have the timetable you describe. I still think that at least one long dynamic loop would improve reliability.
 

Railperf

Established Member
Joined
30 Oct 2017
Messages
2,470
The works to introduce simultaneous arrival and departure at Aviemore and Pitlochry are great if everything runs to time. But when it doesn't - the rigid and slow procedures at the other passing loops/stations slow evrything down and create more delay.
I remember waiting almost 15 minutes at Pitlochry on a northbound service waiting for a late southbound train to come through and clear the line.
The knock on effect of that was having to make additional stops at passing loops as we were out of path. We lost more time as a result!

Arguably all the passing loops could do with lengthening and resignalling to allow traffic to flow better.
 

hexagon789

Veteran Member
Joined
2 Sep 2016
Messages
12,030
Location
Glasgow
Looking at it from an operational view - to run an hourly service - and assuming you could average 60mph, then your trains are going to cross each other every 30 mins or so. If the trains can be booked to leave and arrive at Inverness or Perth at around the same time - then the trains can pass each other at the main station stops half an hour apart.
The half hour sections seem to be Inverness to to Aviemore, Aviemore to Dalwhinnie, Dalwhinnie to Pitlochry , and then Pitlochry to Perth.

Your Northbound service and Southbound services ideally need to pass each other at Aviemore and Pitlochry at station stops. Timed correctly - your southbound service joins the double track at Dalwhinnie a few minuites before the northbound is set to hit the single track. Similarly, the southbound service can hit the double track at Stanley around 5 to 8 mins before the Northbound service.

If double tracking cannot be achieved throughout - would it be better to extend some of the loops into shortish double track lengths be a better idea?
I wonder if re-instating the HST differentials installed in 1984 and removed around 1993 would be worthwhile. They were removed because it was decided they were of limited benefit - only the 'Chieftain' could use them and didn't significantly improve journey times but the shorter ScotRail sets can accelerate much quicker so they may be of more beme fit in producing a higher average speed as you suggest
 

Railperf

Established Member
Joined
30 Oct 2017
Messages
2,470
Hmm. I will have to check for the HST differentiala in our distance chart archive.
 

hexagon789

Veteran Member
Joined
2 Sep 2016
Messages
12,030
Location
Glasgow
Hmm. I will have to check for the HST differentiala in our distance chart archive.
I was informed by two retired BR ScotRail engineers that BR ScotRail installed several HST differentials in the early 1980s. Among the first was on Edinburgh-Aberdeen in 1982 iirc, Perth-Inverness was partially done in 1984 for the 'Chieftain' launch with further sections added in 1985 for an accelerated schedule.

Edinburgh-Glasgow had them installed earlier.

The HML & E-G ones were all removed in 1992-93 as the 158s couldn't use them at the time and were limited to 90mph anyway.

I understand MU ones were reinstated in ~2006 on the Edinburgh/Glasgow for Class 170s.
 

47271

Established Member
Joined
28 Apr 2015
Messages
2,967
Remember also that due to the availability of paths out of Waverley and, in particular, Queen Street, these trains can only depart from, or arrive into, Central Scotland at particular times each hour. It may not be possible to have the timetable you describe. I still think that at least one long dynamic loop would improve reliability.
Yes, paths in and out of Waverley and Queen Street are an issue, but the other major factor in HML flexibility is the continuous 15 mile single section between Ladybank and Hilton Jn. If anything I would improve capacity there before I did anything with Perth-Inverness itself, it's already trying to support an hourly service.

Many a time I've been on the early evening Edinburgh to Inverness train and left Waverley on schedule. Meanwhile the early evening Inverness to Glasgow service set off on time. By the time both met at Dunkeld just before 730pm both found themselves at least 15 mins late because my train got held at Ladybank waiting for the very long single section. And so it goes on...

Anyway, not much of this has much to do with Scotrail HSTs, other than to repeat the observation that the full HST timetable may well make HML reliability noticeably worse than it is at the moment.
 
Status
Not open for further replies.

Top